Metal bending



Jan. 0, 1925. 1,523,714

L. c. PRITNER ET AL METAL BENDING Filed Aug. 15, 1922 [Menlars Patented Jan. 20, 1925.

UNITED STATES PATENT OFFKIE.

LINDSAY C. PRITNER AND HENRY C. DORRIS, OF JOHNS'IOWN, PENNSYLVANIA.

METAL BENDING.

Application filed August 15, 1922.

To all whom it may concern:

Be it known that we, LINDSAY C. PRITNER and HENRY G. DORRIS, citizens of the United States, and residing in the city of Johnstown, county of Cambria, and State of Pennsylvania, have invented certain new and useful Improvements in Metal Bending; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to bending metal and to the dies and apparatus for performing some of the operations in shaping a plate of metal with particular reference to forming railway truck side frames of the type generally disclosed in United States Patent to G. A. Anderson, No. 1,422,074,

dated July 11, 1922.

The type of truck side frame referred to is formed of one metal plate, and all the main members thereof are substantially integral, so that the entire truck sideframe may be said to be composed of one piece of metal, shaped and formed in its various parts to provide the different members, each of which is adapted to perform its proper functions in use.

Prior operations in forming such a truck side frame may consists in taking a plate of metal, preferably of steel or iron, cutting it to shape, then forming flanges on *arious of its edges, and the present invention comprises bending the cut and flanged plate about its intermediate portion until the edges of the flanges are opposite; with the apparatus therefor.

After the steps above mentioned have been completed, the cut and flanged plate is placed on our bottom bending female die, which die is provided with a groove of openbox or U-section, the plate being arranged with its longitudinal intermediate portion above the longitudinally extending groove of the die. After the cut and flanged plate is accurately placed thereon in position, this position being determined by gauges or other stops suitably arranged on or adyacent our die, a male die which is substantially of the .ame length as the bottom die, but of narrower width by an amount about equal to twice the thickness of the plate to be bent, is projected against the plate and forced Serial No. 58 1,933.

downwardly, thereby bending the plate about its intermediate portion until the two sides are opposite each other, but at a small angle with each other.

The female die may be fixed while the male die is movable, or vice versa, or both may be movable as will be readily understood.

The lower edge of the upper die is provided with a removable former of one piece or preferably a pair of wedge-shape portions, which, when placed together and temporarily secured thereon have the form which is desired to be given to the interior of the intermediate bent portion of the frame. The detailed construction of this former will be explained hereafter in more detail.

After the top die has reached the limit of its travel and has pressed the intermediate portion of the plate into the groove of the bottom die, whereby it assumes the form of said bottom die, the pressure on the top die is slightly released and the main portion of the top die withdrawn, leaving the former within the pressed or bent portion of the frame, which portion eventually forms the top arch bar member of the truck side frame.

After this is done the frame is placed in another set of dies, which close the side portions together, making them parallel, but this does not form any part of the presentinvention, and is the subject of another up plication, for pressing metal, filed August 15, 1922, Serial No. 581,932.

Having thus given a general description of our invention, we will now, in order to make the matter moreclear, refer to the annexed sheet of drawings, which form partof this specification, and in which like characters refer to like parts Figure 1 is a side elevation of our bending dies with a pressed metal truck side frame, previously flanged and partially formed, in position on the lower die just before it is bent centrally; Fig. 2 is a bottom plan view of the top bending die with the removable former of wedge shapes in place thereon; Fig. 8 is an end elevation of the bending dies shown in position at the end of the working stroke of the top die; Fig. 4 is a vertical central sectional elevation through apressed metal truck side frame after being bent by our dies and with the removable former in place therein, and Fig. 5 is a section through the former taken on the line V-V of Fig. 2.

Referring now to the characters of reference on the drawings :1 is the top die holder, which may be secured to the platen or plunger of a hydraulic or other press having a stroke of sufficient length and power to perform the operations desired. 2 is a groove or slot in the upper die holder adaptedto receive the upper edge portion of the topdie 4, which is secured therein by means of the bolts 3. I provide grooves on each side ofthe top die, namely, 5, 6, 7 and. 8, of widths, lengths and depths sufficient to receive the corresponding" flanges of the previously flanged plate, so. that when the two portions of the plate are bent toward each other the flanges enter these grooves andallow the bending to proceed without obstruction or deformation of the plate. I also provide projections 9 within the groove 8 which are preferably formed integral with the top die 4, and below these I provide reinforcing blocks 10, which are adapted to iaekup the former 21 and prevent it from bending or distortion during the operation. These blocks 10 may be integral or may be separate and secured in place by tap bolts or otherwise- At the ends of the top die 4 I provide brackets or clevises 11 which are secured in position by the tap bolts 12, the lower ends being bifurcated, with eyes 13, through which the pins. 14 are passed, to

temporarily secure the former 21 in position against the lower surface of the top die. The previously cut and flanged plate from which the truck side frame is formed is 15, while 16 represents the bottom die in gen-- eralQwhich may be secured in place on the lower bed of the platen of the pressand secured thereon by any desired means so that it accurately registers with the top die. The bottom die is provided with a groove 17, which is of open-box form with rounded corners or of Ushape, and this, together with the top die and former provides a matrix in which the top arch bar member of the truck side frame is accurately pressed to shape. The sides of the truck side frame are 18, and the inwardly extending flanged ledges thereof are indicated as 19, while the central intermediate portions of the truck side frame which form the top arch bar member are 20.

It should be noted that the wedges ,21 are tapered to some extent and when placed together they provide a parallel former of rectangular cross-section with rounded corners. e

Having thus described our apparatus, we will now explain the method of operation When the top male die 4 is in the upward position as illustrated in Fig. 1, the previously cut and flanged metal blank 15 is.

placed in position on the female bottom die,

and presses it downwardly into the groove.

17 of the bottom die, whereupon the sides of the blank rise up simultaneously with the corresponding parts of the symmetrical blank substantially opposite each other, as illustrated in Figs. 3 and 4. After this is done the pins 14 are removed, the top die 4 is withdrawn, and the bent plate 15 with the former 21 still therein is removed to an other apparatus for further operation.

Although we have shown the former 21 made of two tapered pieces, we may also make this member of one piece of substantially parallel form, but this would require more force for its withdrawal. .VVe therefore prefer to make this member of two wedge-shaped pieces, for the reason that as one of the wedges is started in its removal movement it at once releases the pressure and reduces the friction of withdrawal.

Either before or after the subsequent operation is performed, the wedges 21 may be withdrawn longitudinally, and to assist in loosening them the ends of one may project slightly beyond the other, so it a may be struck with a sledge to start it, after which it is pulled out in one direction while the other is removed in the opposite direction.

Although we have described and illustrat- 1. The steps in the method of forming a truck side frame, comprising takin 'a previously cut and edge flanged plate, p ac- I ing its inter-mediate .portion over a grooved die, then projecting amale die 'ag'a-instthe intermediate portion only of the plate and forcing said intermediate portion into said groove, whereby the side portions, adjacent the intermediate portion. of said plate are bent towards and at an angle to each other,

without contact of the dies therewith.

2. The steps in the method of forming a truck side frame, comprising taking a previously cut and edge flanged plate, placing the intermediate portion thereof over a die having a groove therein of open-box form, then projecting a registering male die against the plate and forcing said intermediate portion thereof into said groove, wl'iereby the side portions of said plate, adjacent said intermediate portion, are bent toward and at an angle to each other with their corresponding flanges substantially opposite each other, without contact of the dies therewith.

3. The steps in the method of forming a truck side frame, comprising taking a previously cut and edge flanged plate, placing its intermediate portion over a grooved die, then projecting against said portion a male die provided with a forming portion removably attached to its edge, which contacts with said plate, then relatively moving said dies and forcing a portion of the plate into said groove, whereby the side portions of said plate are bent toward each other, and then taking away the securing means of said removable portion, and withdrawing the male die.

4t. The steps in the method of forming a truck side frame, comprising taking a previously cut and edge flanged plate, placing a portion thereof over a grooved female die, then projecting against said portion a male die provided with a removable former consisting of a pair of wedge-shape members adapted to contact with said plate, which together provide the desired shape, then relatively moving said dies and forcing a portion of the plate into said groove, whereby the sides of said plate are bent toward each other with their corresponding flanges substantially opposite, then taking away the securing means of said removable former, then withdrawing the male die and then longitudinally removing the wedgeshaped members from the bent plate.

5. The steps in the method of forming a truck side frame, comprising taking a previously cut and edge flanged plate, placing its intermediate portion over a grooved female die, then projecting against said portion a male die provided with a movable former wider than said latter die and adapted to contact with said plate, then relative- 1y moving said dies and forcing a portion of the plate into said groove, whereby the side portions of said plate are bent toward each other, then taking away the securing means of said former and withdrawing the narrower portion of the male die between the bent portions of the plate and the flanges thereof, which are opposite each other, but spaced apart.

6. Apparatus for forming flanged truck side frames comprising a female forming die having a longitudinally extending groove therein of open-box form, a corresponding male die of lesser width adapted to register therewith, provided with grooves in its sides adapted to receive the flanges of the frame, a removable forming member of greater width than said male die removably secured to the operating edge thereof, and means for relatively moving said dies in registery.

7. A forming die provided with an approximately rectangular open-boX form with rounded corners, a corresponding male die of narrower width provided with a plurality of grooves therein adapted to receive the flanges of a plate to be bent, and a member of greater width than the male die removably secured thereto.

8. A female forming die having a groove therein of open-box form, a corresponding male die of lesser width than said groove adapted to register therewith, a removable forming member of greater Width than said male die composed of a pair of oppositely tapered portions removably secured. thereto, and means for relatively moving said dies in registry.

9. The combination of a female forming die having a groove therein of approximately rectangular form with rounded corners, a corresponding male die of less width than said groove provided with a bifurcated clevis member at each end, and a pin passing through each clevis in which is mounted a forming member of greater width than said male die.

10. The combination of a female forming die having a groove therein of approximate- 1y rectangular form with rounded corners, a corresponding male die of less width than said groove provided with a bifurcated clevis member at each end, a pin passing through each clevis in which is mounted a forming member of greater width than said male die, and composed of a pair of oppositely tapered members.

In witness whereof we hereunto affix our signatures.

LINDSAY O. PRITNER. HENRY C. DORRIS.

groove therein of 

